Overview of ISSU on ASR 9000 with IOS XR 64 Bit

In-Service Software Upgrade (ISSU) provides the ability to upgrade the IOS XR 64 Bit version on ASR 9000 with minimal disruption
on the control plane and forwarding plane. ISSU supports upgrading an image from a lower to a higher version. ISSU supports
zero topology loss (ZTL) and causes only a minimal packet loss of less than six seconds.

You can perform ISSU
installation in a single step or as multiple phases. You need to perform the
pre-installation tasks before executing ISSU. During the pre-installation tasks
and ISSU execution, V1 refers to the image currently running on the router and
V2 will be the upgraded image.

ISSU execution contains the following phases:

Prepare phase: The installable files are pre-checked and loaded on the router before activation. This phase is optional.

Activate phase: The new image (V2) is downloaded to all nodes in the router replacing the old image (V1). This phase can be
run in step-by-step phases like Load, Run, and Cleanup or by using a one-shot Activate phase.

Note

The Prepare phase is optional and can be skipped because the Load phase prepares the package if Prepare phase was not performed before the Load phase.

Commit phase: The ISSU installation is complete with V2 on all nodes.

ISSU supports upgrading the System Admin VM and XR VM individually. Using ISSU, the System Admin VM and XR VM can also be
upgraded sequentially. The upgrade sequence is System Admin ISSU followed by XR ISSU. Committing the upgrade from XR VM commits
both the System Admin and XR software. But, committing the upgrade from System Admin VM commits only the System Admin software.

Note

When RSP1 is the active RP and System Admin VM ISSU is triggered on Cisco ASR 9000 with IOS XR 64 bit, there is an additional
VM switch over compared to performing System Admin VM ISSU from RSP0. This is an expected behaviour.

Restrictions and
Usage Guidelines

ISSU on ASR 9000 with IOS XR 64 Bit is supported only on few third generation ASR 9000 Series Ethernet LCs, RSPs and RPs.

The third generation of LCs include:

A9K-8X100G-LB-SE

A9K-8X100G-LB-TR

A9K-8X100GE-SE

A9K-8X100GE-TR

A9K-4X100GE-SE

A9K-4X100GE-TR

A9K-MOD400-SE

A9K-MOD400-TR

A9K-MOD200-SE

A9K-MOD200-TR

The third generation of RSPs and RPs include:

A9K-RSP880-SE/TR

A9K-RSP880-LT-SE/TR

A99-RSP-SE/TR

A99-RP2-SE/TR

ISSU is not supported on the ASR 9000 Series 24-port and 48-port dual-rate 10GE and 1GE line cards:

The line cards include:

A9K-24X10-1GE-SE

A9K-24X10-1GE-TR

A9K-48X10-1GE-SE

A9K-48X10-1GE-TR

Pre-Installation
Tasks

Pre-Installation Tasks

Before performing ISSU on ASR 9000 with IOS XR 64 Bit, complete the following tasks.

Configure NTP in XR VM. Once you configure NTP on XR VM, System Admin VM automatically syncronizes with NTP running on RSP.
If NTP server is not available, configure clock on both XR VM and System Admin VM in configuration mode and make sure that
your clock is set to the correct location and timezone.

Ensure that the dual RP and RSP systems are synchronized and they are in active and standby roles respectively using the show redundancy summary command. The line card status should be Final Band or Running.

Ensure that firmware on linecards, RSP, and RP is upgraded to the latest version. You can upgrade the router cards in a single
step by using the upgrade hw-module location all fpd all command. Use the show hw-module location locationfpd command to verify the firmware versions.

Check the disk storage space on both System Admin VM and XR VM and ensure that sufficient disk space is available. Remove
files like show-tech, cores, kernel dumps, manually created text, log, debug information and so on.

This example shows verifying the disk storage space for System Admin VM and XR VM on RSP0. You also need to verify the disk
space on the standby RSP (RSP1). If required you can verify the disk storage on line cards using the show media location command.

Check the repository to validate that packages, images, or SMUs are populated properly in the router's repository by using
theshow install repository command. There should be a one to one relationship between V1 and V2 images and SMUs. For example, if you install a SMU on
V1, you also need the corresponding V2 version in the repository to execute ISSU.

Extract the ISO image in System Admin VM or XR VM depending on the version of the image.

For IOS XR versions prior to 6.5.1: You should extract the ISO image in XR VM as well as in System Admin VM because the system
can only use packages in RPM format.

For IOS XR version 6.5.1 and onwards: System automatically extracts the system admin package from the ISO file once you mentioned
the file name while executing ISSU. You only need to extract the XR package separately.

ISSU on ASR 9000 with IOS XR 64 Bit: Single Phase Installation

This section shows how to perform ISSU on ASR 9000 with IOS XR 64 Bit in a single step. You can either upgrade the system
or install a patch in a single step. The system upgrade is done using an ISO image file, while the patch installation is done
using packages and SMUs.

You should perform the following steps before performing this task:

Copy the package to be installed either on the router's hard disk or on a network server to which the router has access.

Ensure that dual route processor (RP) system with standby is in "is ready" state.

Preform the following steps to upgrade the system or install a patch in a single step.

Note

Depending on whether you are installing a System Admin package or a XR package, execute these commands in the System Admin
EXEC mode or XR EXEC mode respectively

(Optional) Prepare the installable files by using the install prepare issu package_name command. During the prepare phase, pre-activation checks are made, and the components of the installable files are loaded
on to the router setup.

ISSU on ASR 9000 with IOS XR 64 Bit: Multi Step Installation

This section shows how to perform ISSU on ASR 9000 with IOS XR 64 Bit in multiple steps.

You should perform the following steps before performing the steps in this task:

Copy the package to be installed either on the router's hard disk or on a network server to which the router has access.

Ensure that dual route processor (RP) system with standby is in "is ready" state.

Perform the following steps to upgrade the system or install a patch in multiple phases.

Note

Depending on whether you are installing a System Admin package or a XR package, execute these commands in the System Admin
EXEC mode or XR EXEC mode respectively.

Note

You should update the System Admin VM first and then update the XR VM. IOS XR 64 bit ISSU will fail if the System Admin VM
is not updated first.

(Optional) Prepare the installable files by using the install prepare issu package_name command. During the prepare phase, pre-activation checks are performed and the components of the installable files are loaded
on to the router setup.

This step downloads the new image (V2) to all nodes in the router. The new image is checked for compatibility to ensure that
the router can be upgraded. At the start of the Load phase, the router configuration mode is locked, and you cannot perform any configuration on the router until ISSU completes
the phase. At the end of this stage, all standby nodes run V2 and all active nodes (including all line cards) still run the
original software images (V1).

Starts the run phase by issuing the install activate issu run command.

For System Admin VM :

sysadmin-vm:0_RSP0# install activate issu run

For XR VM:

RP/0/RSP0/CPU0:router# install activate issu run

This phase starts version switch from V1 to V2. All the packages that have been prepared are activated to make the package
configurations active on the router.